Duration Of Effect

Soil acidity is not permanently corrected by a
lime application. The original supply failed to prove lasting, and the
relatively small amount given the land in an application will become
exhausted. The duration depends upon the degree of acidity, the nature
of the soil and its crops, and the size of the application. Experiments
at the Pennsylvania experiment station have shown that an application
only in sufficient amount to correct the existing acidity at the time
of application will not maintain an alkaline condition in the soil,
even for a few months. There must be some excess at hand to unite with
acids as formed later in the crop-rotation, or limings must be given at
short intervals of time to maintain alkaline conditions.

Experience causes us to assume that enough lime should be applied at
one time to meet all requirements for a single crop-rotation of four,
five, or six years, and, wherever lime is cheap, the unpleasant
character of the labor inclines one to make the application in
sufficient amount to last through two such rotations. It is a
reasonable assumption, however, that more waste results from the
heavier applications at long intervals than from light applications at
short intervals. In any event need will return, and soil acidity will
again limit income if applications do not continue to be made.